Relationship between increased knee joint line obliquity after medial open-wedge high tibial osteotomy and patient-reported outcome measures.

INTRODUCTION: This study evaluated the correlation between postoperative knee joint line obliquity after medial open-wedge high tibial osteotomy and patient-reported outcome measures excluding excessively overcorrected knees. This study further identified preoperative radiological factors related to the increased postoperative knee joint line obliquity. MATERIALS AND METHODS: We retrospectively evaluated patients who underwent medial open-wedge high tibial osteotomy between March 2013 and March 2021. Postoperative excessively overcorrected knees with hip-knee-ankle angle > 7° were excluded. We investigated radiological parameters and patient-reported outcome measures preoperatively and at the last follow-up. The following radiologic parameters were measured: hip-knee-ankle angle, weight-bearing line ratio, mechanical medial proximal tibial angle, mechanical lateral distal femoral angle, lateral distal tibial angle, joint line convergent angle, knee joint line obliquity, ankle joint line obliquity, hip abduction angle, tibial posterior slope, Carton-Deschamps index, and patella tilting angle. Clinical outcomes were evaluated using Japanese knee outcome measures. This assessment criterion is based on the Western Ontario McMaster Universities Arthritis Index and MOS Short Form 36. Multiple regression analysis was performed to evaluate the association between postoperative knee joint line obliquity and patient-reported outcome measures or preoperative radiological factors (P < .05). RESULTS: A total of 52 knees were included. The mean age at the time of the surgery was 61.6 ± 9.0 years and the mean follow-up period was 30.6 ± 10.1 months. Increased postoperative knee joint line obliquity was associated with lower Japanese knee outcome measures. The preoperative hip-knee-ankle angle was significantly associated with postoperative knee joint line obliquity. CONCLUSIONS: Increased knee joint line obliquity after medial open-wedge high tibial osteotomy is associated with inferior clinical outcomes. Care should be given to the center of the rotational angulation in around-knee osteotomy to avoid postoperative increased knee joint line obliquity. LEVEL OF EVIDENCE: Retrospective comparative study, Level III.

Influence of different standing positions on anatomical parameters of coronal whole-leg weight-bearing radiographs in preoperative planning for high tibial osteotomy.

Purpose: The purpose of this study was to assess the differences in lower limb global alignment and anatomical parameters of coronal whole-leg radiographs, which were generally used in preoperative planning for high tibial osteotomy (HTO), according to different weight-bearing standing positions. Methods: Between April 2021 and December 2022, 176 patients (60 males and 116 females) were investigated. Full-weight-bearing coronal whole-leg radiographs were obtained with the patella centred on the femoral condyle. Patients were divided by Kellgren-Lawrence grade (KL-0, KL-I, KL-II and KL-III) and assessed in two standing positions: legs closed and legs spread. Patients with flexion contractures or those unable to stand with full weight bearing were excluded. The mechanical distal femoral angle, medial proximal tibial angle (MPTA), femorotibial angle, joint line convergence angle, percentage weight-bearing line (%WBL) and hip-knee-ankle angle (HKAA) were measured. The Student's t test was used to compare the two standing positions. A p value < 0.05 indicated a statistically significant difference. Results: The MPTAs of legs closed standing and legs spread standing were 84.9 ± 2.6° and 85.1 ± 2.4° in KL-0, 84.7 ± 2.0° and 84.9 ± 2.1° in KL-I and 85.0 ± 2.43° and 85.4 ± 2.4° in KL-II, respectively. There were statistically significant differences in the MPTA between the two standing positions in KL-0, KL-I and KL-II. In contrast, the %WBL and HKAA did not change regardless of the standing position. In the KL-III group, no statistical significance was observed for any of the anatomical parameters. Conclusion: Several anatomical parameters were changed between the legs closed standing and the legs spread standing positions. It was suggested that the standing position should be taken into consideration in the planning for HTO. Level of Evidence: Level IV, Case series with no comparison group.

Temporal changes in tibiofemoral relationship following anterior cruciate ligament injury: Implications for rotational dynamics and clinical outcomes.

Purpose: This study aims to elucidate changes in the tibiofemoral relationship over time following anterior cruciate ligament (ACL) injury, and investigate the correlation between the tibiofemoral relationship and patient-related outcome measures (PROMs). Methods: Overall, 203 primary ACL reconstructions were performed using autologous hamstring grafts. Medial and lateral anterior tibial translation (ATT) in the sagittal plane and tibial tubercle-trochlear groove (TT-TG) distance in the axial plane were measured using pre-operative magnetic resonance imaging and post-operative computed tomography. The difference between pre-operative and post-operative values for each parameter was calculated: ΔMesdial ATT, ΔLateral ATT and ΔTT-TG distance. The correlation between each calculated value and the time elapsed since ACL injury, and the correlation between each calculated value and PROMs-evaluated using the Knee Injury and Osteoarthritis Outcome Score (KOOS)-were assessed. Results: Sixty-four patients were enroled. Medial ATT, lateral ATT and TT-TG distance were significantly different pre-operatively compared to post-operative values, with the tibia translating anteriorly and rotating internally relative to the femur. ΔMedial ATT, ΔLateral ATT and ΔTT-TG distance were 1.6, 8.8 and -4.8 mm, respectively. A negative correlation was observed between the ΔTT-TG distance and the time elapsed since the injury (r = -0.44, p < 0.01). No correlation was found between ΔMedial ATT and the time elapsed since the injury, nor between ΔLateral ATT and the time elapsed since the injury. Neither the ΔMedial ATT, ΔLateral ATT, nor ΔTT-TG distance correlated with the pre-operative or post-operative KOOS subscale scores. Conclusions: The tibia underwent internal rotation relative to the femur over time following ACL injury, highlighting the importance of assessing rotational changes in ACL-injured knees. Level of Evidence: Level Ⅲ.

Nontraumatic Chronic Subcutaneous Extensor Digitorum Longus Tendon Rupture in a Recreational Runner: A Case Report.

CASE: Nontraumatic chronic subcutaneous rupture of the extensor digitorum longus (EDL) tendon is rare. A 66-year-old man, recreational runner, suddenly injured his EDL tendon while walking. We surgically reconstructed the ruptured EDL tendon with a free palmaris longus tendon graft. During the surgery, an osteophyte was found to have penetrated the ankle joint capsule and was considered the cause of the tendon rupture. Active toe extension was restored, and the patient completed a 10-km race at 2 months postoperatively. CONCLUSION: EDL tendon reconstruction using a free palmaris longus tendon graft is an effective surgical option for athletes.